Saturday's shooting rampage in Tucson, Ariz. — which left Rep. Gabrielle Giffords fighting for her life and killed or wounded at least 19 others — shook the Capitol like no event since 9/11.

Like the terrorist attacks nearly a decade ago, the Congressional response to the Arizona shootings has largely transcended party affiliation: Members universally condemned the tragedy, put their work on hold and called for a new tone in Washington.

Majority Leader Eric Cantor (Va.) immediately announced that all legislative activity on the House floor would be suspended — including a planned vote on a controversial, and highly partisan, health care repeal bill. He later announced that the House would consider at least one resolution Wednesday honoring Giffords and the victims. Democrats and Republicans said politics must be put aside to recognize the lives lost, which included a Giffords aide, a federal judge and a 9-year-old girl. A Democratic leadership aide said Cantor's move "turned the heat down on the burner" and will help make it possible for the Hill community to "stop and think about what happened."

"An attack on one who serves is an attack on all who serve," Speaker John Boehner (R-Ohio) said Sunday morning in brief remarks from West Chester, Ohio.

Roughly 40 people gathered outside the Capitol on Saturday night for a vigil, and House leaders held a bipartisan conference call Sunday afternoon to update Members, their spouses and chiefs of staff on the incident. Flags on the House side of the Capitol were flown at half-staff for Gabe Zimmerman, the 30-year-old Giffords aide who was killed.

In many ways, the Hill reaction mirrored that of Members in the days following Sept. 11, when Democrats and Republicans quieted their partisan bickering and talked about finding new opportunities to work together.

A somber Democratic Caucus Chairman John Larson (Conn.) said Saturday's shooting could actually lead to more civility.

"There used to be a time when we would assemble because the whole issue of civility had gotten to the point where there wasn't an awful lot of seeming discussion," Larson said after meeting Sunday with some of Giffords' staff. "I don't know if that necessarily will be resurrected again, but I do think something along those lines in terms of the comity needs to be extended from one Member to another and trying to understand and relate to the personal stresses that exist on people and their families serving here."

Other Members said the incident should serve as a reminder that words matter, and that they have a responsibility to mind what they say and how they say it.

"Words do have consequences," Rep. James Clyburn (S.C.), the No. 3 Democrat in House leadership, said Sunday. "I think that what has happened here is that the vitriol has gotten so elevated until people feel emboldened by this ... they go out and do things that all of us pay a great price for."

"We live in a world of violent images and violent words, but those of us in public life and the journalists who cover us should be thoughtful in response to this and try to bring down the rhetoric, which I'm afraid has become pervasive in our discussion of political issues," Senate Majority Whip Dick Durbin (D-Ill.) said Sunday on CNN's "State of the Union." "The phrase 'don't retreat ... reload,' putting cross hairs on Congressional districts as targets, these sorts of things, I think, invite the kind of toxic rhetoric that can lead unstable people to believe this is an acceptable response."

Former Alaska Gov. Sarah Palin has used that phrase, and the imagery refers to Palin's "hit list" of Members whom she wanted defeated in 2010. Durbin was careful to note that he was not directly tying them to Giffords' shooting, but he said there is an "obligation" for public officials to speak up when rhetoric goes too far. Republican aides, meanwhile, bristled at what they perceived as a Democratic attempt to tie the shooting to Palin or the tea party movement, noting that the suspect has no known political affiliations.

Giffords had herself condemned Palin's imagery in a March MSNBC interview.

"We're on Sarah Palin's targeted list. But the thing is, the way that she has it depicted has the cross hairs of a gun site over our district. The more people do that, they've got to realize there's consequences to that action," Giffords said. "All of us have to come together and say there's a fine line here."

Members said they hoped the shooting would not impede Members' ability to interact with their constituents.

"We must, in a democracy, have access to our constituents," Congressional Black Caucus Chairman Emanuel Cleaver (D-Mo.) said Sunday on NBC's "Meet the Press." "I think what we are seeing, though, is you know the — the public is being riled up to the point where those kinds of ... events and opportunities for people to express their opinions to us are ... becoming a little volatile."

Former Rep. Tom Perriello (D-Va.) told Roll Call that he immediately thought of the staffers who were injured or killed.

"I think about the number of times I asked my team to be in contentious situations, it just gives one pause," said Perriello, whose town hall meetings in Southside Virginia in 2009 and 2010 were often raucous. He also saw his own family members threatened when someone cut gas lines to his brother's home.

Giffords' Arizona colleague Rep. Trent Franks, a conservative Republican, characterized the shooting as "an attack not only on freedom and the country itself" but also "an attack on humanity."

"When she was out doing her job as a Member of Congress, some deranged degenerate shot her down," said Franks, who also appeared on "Meet the Press" Sunday, adding, "A lot of people try to make the distinction between someone as conservative as I am and a Gabby Giffords. But I will tell you that never one time did even the slightest cross word or unkindness ever passed between us. This is a precious, decent woman that did not deserve what happened to her."

House Minority Whip Steny Hoyer (D-Md.), appearing on CBS' "Face the Nation," called the shooting "an attack on democracy itself, on the ability ... to come together to talk to one another.

"That's what democracy is all about—Representatives listening to their constituents and trying to reflect their views."

Jackie Kucinich, Jessica Brady, John Stanton and Christina Bellantoni contributed to this report.